Piston packing



T. G. SAXTON.

PISTON PACKING- PPLICATIQN man APR.10, 1917.

Patented Feb. 28, 1922.

2 SHEETS 'SH EE T I.

T. G. SAXTON.

PISTON PACKING.

APPLICATION FILED APR. 10, 1911.

Patented Feb. 28, 1922.

2 SHEE H #71 out the slots; I

UNITED STATES PATENT OFFICE.

THOMAS GUNN'I SAXTON', 0F LEXINGTON, KENTUCKY, ASSIGNOR T0 EMELIUS M.

. MCKEE, 0F LEXINGTON, KENTUCKY. i

- PISTON PACKING.

- Application filed April 10,1917. 'Serial No. 161,089. v

To all whom it may concern:

Be it known that I, THOMAS G. SAxroN, a

citizen of the United States, residing at Lexington, in the county of Fayette and State of Kentucky, have invented certain new and useful Improvements in Piston Packings; and I do hereby declare the fol lowing to bea full, clear, and exact description of the invention, such as will enable others skilled in the art towhich it appertains to make and use the same.

This invention relates to pistons or piston packing, and more particularly to pistons of that class or type in which a metallic packing is used'for maintaining the piston fluidtight within the working cylinder of a steam, gas or other motive-power engine.

The objects of the invention areto provide a simple, light, eflicient and inexpensive 'metallicpacking of the character referred to in Which conoidal split rings are used and which the packing presses circumferentially against the cylinder wallsin a uniform manner.

A further object of this invention'is to provide a packing havinga light anti-friction outer member and .an inner member which provides. the necessary elasticity for the same. V

A further object is to provide an improved form of inner member of lightconstruction and possessingthe necessary elasticity.

The invention will be readilyunderstood from an inspection of the accompanying drawings and the following detailed de scription of the constructions illustrated therein. 4 i v' Fig. 1 is a longitudinal sectional view of a piston illustrating a number of my im-- proved packing rings arranged therein;

,Fig. 2 is a section taken on line 22* of Fig. 1, clearly showing the slots in the wing of the inner ring;

Fig. 3 is a side elevationv of the inner ring- 1 p 7 F ig'. 4 isfa section thereof;

Fig-5 is alview of a similar ring with- Fig.. 6- is still anotherformshowing a non slotted inner ring with an inner stifien- Fig. 7 "is a detailed elevation of said stifiening member;

Fig. 8-isa section of the ring and inner member shown in Fig. Grand- Fig. 9 shows a single packingring as actually used in practice; therelative size of inner and outer rings and their arrangement in a piston groove being illustrated.

Referring to the drawings, in which the same reference characters are used to designate corresponding parts in different views, 1 denotes the cylinder of a steam, gas-or other engine provided with a piston 2 havlng a disk-like head 3 and an intermediate connecting portion 2' forminga' recess for the receptlon of one or more of the improved packing rings.

As shown in Fig. 9, a single packing ring comprises an outer solid split ring orband 4 and an inner ring 5 split at 6. The'inner ring 5 may be formed of astrip of metal,

preferably spring steel and die pressedaon. a

mandrel to true circular form and of a size to fit exactly within an outer ring f so that when removed from the mandrel it tends, to open and assume a normal irregular-circular form or elliptical shape. f The form of these inner rings is that of a frustrum-shell with an open top and base, except that the basev is provided with an inwardly extend ing flange 6. The inclined walls orwings 7 of these inner rings are adapted to fit ,within similar interior surfaces on the outer rings 4; and the base or lateral flanges 6' are adapted to lit to and bear against one'veritical side wall of the pistongroove, the

other side thereof ina similarmanner-affordinga bearing for the base f of the outer ring. 5 -As shown sectioned in Fig. 9, the inner and outer rings constitute-sections of reversely arranged triangles, the outer one being solid and the inner hollow, with the apex of the outer flush with the base 6' of the inner ring and the apex of the inner flush with the base 4: of the outer. The

inclined surfaces between the two provide a bearing surface whereby adjusting movement is affordedand whereby the inner rings may adjust themselves outwardly relative to the exterior rings; Therings 4 being made of relatively soft anti-friction mabecomes flush with the outer wearing surface of the outer ring {t thereby sealing the split in said Outer ring 4. i

Theseinner rings may or inay not be provided with open-ended slots arranged in'the wings 7 thereof to compensate for lateral expansion and contraction, suchslots preferably extending from a point near the base to the extremity thereof. And it'is also within the contemplation of this invention to slot the base flanges 6.

The outer split rings 4 are madeof a softer anti-friction material such as aluminum alloy, or preferably'of the same ma terial as that of which the piston is made so that the relative rates of expansion will be the same. They are preferably made solid'and triangular-shaped in cross section, "as shown in Fig. 9, although it is evident When the inner rings '5', which are nor- -m'ally in expanded elliptical shape, are

placed Within the outer rings 4 and as sembled in the piston grooves Within the cylinder, the inner spring ring tends't'o assumeits elliptical shape, forcing the outer circular packing member firmlyagainst the cylinder wall, providing a uniform internal pressure circumfcrentially thereof.

And as will be "seen, the inner ring 5'beting normally in an expanded elliptical form, atwh'en contracted to the trulycircular form, ---and placed within its outer ring, with its cone fbase 6f substantially flu'sh' with the "thinner edge or apexof the cone of the overlying outer ringfand the combinedwidth "oftheassembled rin'g's approximately equal t'olthewidth of the groove in the-piston in whic h'they are fitted, so that the base of one sidewallofsaid groove, whilethe base of-"the 'cqrre' of the inner rin bears agai st "the opposite side wall of said groove, the combined action of the two rings is exerted in forcing the periphery of the outer ring against the injiie'r'wall of the cylinder uniformly around the entire circumference thereof and the"thickeredge of the outer that other shapes are contemplate-(1,. such' the cOIieof-the' outer ringwill bear against man than:

are common to all li'eatvvengines and are caused by the expansive forceof theriiigs against the walls, which, being at a higher temperature and hence softer, are more susceptible to wear due to the travel ofthe' ton and rings. And with the present construction of packing rings the desired re sults are obtained even plu cylinders without regrinding the, same a'nd without losing any of the efliciency of loosene'ss in thegroove. v p

, When thepacking rings are usedin-pai rs or multiples thereof, each distinct ring-acts independently of the, other in the piston groove and each 1-in; is free to-shift both laterally and outwardly to adjust itself with respect to the otherring and to the cylinder wall and each ring'also acts as a seal for the nextadjacent ring.

In ,Fig.

0 one of the inside rings is shown as provided with the usual slit 6 but without the slots 7 in the wings, 1,

c The i proved inner rings shown v in Figs. 6, 7 and 8 are adapted to replace siicli an inner ring as is illustrated in Eig l and donsists of an outer split casing 8 oithe same shape and cross section as the ring shown in e wi t e iitio fih t th s-enema casing 1s made of mild steel, brass, aluminum or othernon-spring metal and stamped or otherwise constructed that in its normal relaxed shape it fits in true circular form with the outer true circi'ilar ring 4' heretofore described.

lVithin thisinner casing 8 is adapted to fit'a spring inernberrherein shown as split ring 11, preferably mad e'of carbon steel and preferably of a cross-section to correspond with the inside conformation of the-casing 8 so that the force of the spr'ingjsevehly distributed across the face'of contact thereof.

Vhen the inner ring 10 and casing; dare j assembled within the outer ring 4;, a g inost" perfect internal ci rcular,pressurefagainst the cylinder wall is created, due to the fact that the irregular and uneven outward pressure of the spring is'transmitted'to the cylinder wall by means of *the two concentric circular rings. An in this case .even greater'li"htness of construction may be realized since the inner casing 8,may 'beniadegdf lighter i'q i y p g ring such as shown in Figt? V It is of course understood that these improved inner casings, spring members and outer rings 4 may be used either singly, as in Fig. 9, or in multiples thereof, as in Fig. 1.

A packing constructed as in Fig. 6 has many advantages over other devices in that the inner rings 8 are of stamped non-spring metal of true circular form and do not tend to spring into elliptical or irregular shape and hence make a true fit with the outer rings 4 which are also of true circular shape. Furthermore, the inner spring metal members 10 give the rings the required resiliency to force the outer member unfiormly against the cylinder wall. And these outer rings being made of non-friction metal do not score the walls thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1.v A metal packing-ring comprising a hollow frustum provided with an inward-extending, marginal, basal flange, and a laterally inclined wing having open-ended, transversely-disposed slots to compensate for lateral expansion and contraction.

2. The combination with an outer ring having an inclined wall, ofa resilient inner ring having an inwardly extending marginal flange adapted to bear against the vertical side wall of a piston-groove, and a wing inclined thereto and bearing against the inclined wall of the outer ring, said inclined wing also being provided with open-ended, transversely-disposed slots to compensate for lateral expansion and contraction. 4

3. A piston packing comprising an outer ring composed of aluminum all-0y and. having an interior inclined surface and an inner resilient ring having a laterally extending wing inclined to conform to the inclined surface of the overlying outer ring and also having an inwardly extending marginal flange arranged to bear against the vertical wall of the piston groove, said inclined wing having open-ended slots therein to compensate for lateral expansion and contraction.

4. A piston packing comprising an outer split ring of substantially triangular form in cross section constructed of relatively soft metal, and an inner resilient ring constructed of spring metal laterally inclined and fitting within and against a correspondingly inclined surface of the outer ring and having radially extending open-ended slots therein, and an inwardly extending marginal flange arranged to bear against the vertical wall of a piston groove.

In testimony whereof I affix my signature in the presence of tWo witnesses.

THOMAS GUNNI SAXTON.

Witnesses:

BRADLEY DnisoN, R. A. NORRISS. 

